Switching property of 4 MV laser-triggered multistage switch

The design and experimental results of the 22-stage 4 MV laser-triggered multi-channel switch are reported. The field distribution of the laser-triggered gap and the serial selfbreakdown gaps are symmetrical. The selfbreakdown gap is designed as an annular gap formed by disk electrodes and a column insulator stack. The field distribution of the switch section is regulated by the voltage-holding field regulation ring. The experimental results show that the maximal deviation of the selfbreakdown voltage is less than 5%. The difference between the average selfbreakdown voltage and the linear fit is less than 5%. The switch is triggered by a 4 ns, 35 mJ Nd:YAG fourth harmonic laser pulse. The delay is about 25 ns as the working ratio is 85%±3% of the selfbreakdown voltage. The maximal deviat